Macaques and Gercopithecus, giving to them the greenish hue
which characterises so many of the last two genera. There are
no laryngeal air sacs as in the Macaques. There are not more
than seven species.
The genus Oereopitliecus (the G-uenons) represents in Africa
the Oriental and Palaearctic Macaques; the genus has a long
tail. The cheek pouches are larger than in the genus Macaeus.
The ischial callosities are less extensive than in that genus. A
tooth character also distinguishes this genus from Macaeus ; the
last molar of the lower jaw has, as a very general rule, only
four cusps instead of the five which are found in Mhcacus. The
supraciliary ridges in the skull are by no means so marked as in
the allied genera.
One species, the Talapoin, O. talapoin, has been separated into
a distinct genus, JM/iopithecus, on. account of the fact that the
lower molars have only three tubercles instead of the usual four.
But if this be done, then Cercopithecus vnoloneyi, which has a
lower molar with five tubercles, should also be separated.
The genus Cercopithecus is limited to Africa, and its numerous
species have often a very limited range. They are frequently
rather brightly coloured, with blue and white patches on the face.
The Diana Monkey has a pointed white beard. Of the Vervet
Monkey (O. lalandii) a curious fact was noticed at the Zoological